Analog Devices Inc./Maxim Integrated MAX6726KATGD3+

Overview

MAX6726KATGD3+ from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in an 8-pin SOT23 package, monitoring VCC1 (primary), VCC2 (secondary), and RSTIN (auxiliary) supply rails with factory-trimmed thresholds of 4.625V (VTH1), 3.075V (VTH2), and 626.5mV reference for RSTIN. It provides push-pull active-low RST and RST2 outputs, manual reset input (MR), watchdog timer (1.12s normal / 35s startup timeout), and guaranteed reset validity down to VCC1 or VCC2 = 0.8V. It is used in multivoltage embedded systems requiring reliable power-on reset and brownout detection.

For engineers reviewing the MAX6726KATGD3+ datasheet, MAX6726KATGD3+ pinout, MAX6726KATGD3+ application, or MAX6726KATGD3+ equivalent, key selection criteria include its dual-supply monitoring capability with adjustable third-rail support, 210ms (min) reset timeout, push-pull output drive referenced to VCC1/VCC2, and operation across –40°C to +85°C industrial temperature range.

Technical Context

The MAX6726KATGD3+ integrates three independent voltage comparators - one for VCC1 (4.625V threshold), one for VCC2 (3.075V threshold), and one for RSTIN (626.5mV internal reference) - each feeding into a shared reset timeout timer. Its dual-mode watchdog uses a 35s minimum startup period followed by a 1.12s minimum normal timeout, triggered by WDI edge transitions.

Reset assertion is synchronized across all monitored inputs: VCC1/VCC2 undervoltage, RSTIN falling below 626.5mV, MR low, or watchdog timeout. The device guarantees correct reset logic state when either VCC1 or VCC2 remains ≥0.8V, and supports both push-pull RST (VCC1-referenced) and RST2 (VCC2-referenced) outputs with VOL ≤0.4V at 3.2mA sink.

Key Specifications

Pinout & Package

MAX6726KATGD3+ is housed in an 8-pin SOT23-8 package (2.0mm × 2.1mm × 1.0mm height), surface-mount, lead-free (RoHS-compliant), with thermal pad exposed on bottom for enhanced power dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX6725KAUTD3+, MAX6726KATGD3+ eliminates external pullups via push-pull outputs and improves system-level noise immunity through guaranteed 0.8V reset validity; versus TPS3808G33DBVR, it adds RSTIN-based third-rail supervision and dual-mode watchdog - essential for complex multivoltage platforms.

Availability

MAX6726KATGD3+ is available at Aetrix Electronics and suitable for industrial PLCs, telecom line cards, server motherboards, portable medical devices, and battery-operated equipment requiring stable component supply and long-term production continuity.

Supply support for MAX6726KATGD3+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for industrial, computing, and communications markets, with emphasis on reliability and integration.

The MAX6715–MAX6729 family delivers compact, ultra-low-power supervisory solutions for multivoltage systems, targeting applications where simultaneous monitoring of primary, secondary, and auxiliary rails is critical to system integrity.

FAQ

What is the reset timeout period for MAX6726KATGD3+?

The MAX6726KATGD3+ has a fixed minimum reset timeout period of 210ms, as indicated by the "D3" suffix in its part number. This delay ensures the microprocessor completes power-up initialization before release from reset, and is guaranteed over the full –40°C to +85°C operating temperature range.

Does MAX6726KATGD3+ support monitoring a third voltage rail?

Yes, MAX6726KATGD3+ supports third-rail monitoring via its RSTIN pin, which compares an external voltage against a precise 626.5mV internal reference. By connecting a resistor divider from the target rail to RSTIN and GND, users can set custom reset thresholds down to 0.62V - enabling supervision of auxiliary, battery, or standby supplies.

What are the output types for RST and RST2 on MAX6726KATGD3+?

Both RST and RST2 on MAX6726KATGD3+ are active-low push-pull outputs: RST is referenced to VCC1 and RST2 to VCC2. This eliminates the need for external pullup resistors and allows direct interfacing with µP reset pins operating at different voltage levels - a key advantage over open-drain alternatives like MAX6725KAUTD3+.

How does the watchdog timer function on MAX6726KATGD3+?

The MAX6726KATGD3+ watchdog operates in dual-mode: after any reset event (power-up, MR, or timeout), it enters a 35s minimum startup period to accommodate lengthy firmware initialization; then switches to a 1.12s minimum normal timeout. A rising or falling edge on WDI resets the timer - ensuring software liveness without requiring precise pulse timing.

Is MAX6726KATGD3+ compatible with low-voltage operation down to 0.8V?

Yes, MAX6726KATGD3+ guarantees correct reset output logic state even when VCC1 or VCC2 falls to 0.8V - a critical feature for brownout detection in systems with wide input voltage ranges. This specification is production-tested and ensures reliable fault signaling during gradual supply collapse, unlike many supervisors that fail below 1.2V.